Plumb-bob



(No Model.)

f H. M. FULLER.

PLUMB BOB. v No. 485,376. Patented Noml, 1892.

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PATENT OFFICE.

HERBERT M. FULLER, OF PHILADELPHIA, PENNSYLVANIA.

PLUMB-BOB.

SPECIFICATION Application filed March 8, 1892.

To all whom it may concern:

Be it known that I, HERBERT M. FULLER, a citizen of the United States, and a resident of the city and county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Plumb-Bobs, of which the following is a specification.

My invention relates to improvements in plumb -bobs, and particularly to improvements in surveyors plumb-bobs; and the object of my invention is to furnish a plumb-bob with an extensible point which may be advanced from time as its extremity is wornaway, and which may at trifling expense be entirely renewed. The points on plumb-bobs, and particularly those on the ones used by surveyors, are usually made of steel and attached to the body of the plumb-bob by screwing them into its end. These points are subjected to very hard usage, being frequently used to make scratches or marks on stone and bricks and for other purposes of a similar nature. The consequence is that the points soon become worn away and the plumb worthless.

My improved plumb-bob is furnished with a long point or spindle, which passes up into the interior of the plumb-bob, and which can be operated by means of a screw in order to push it out beyond the body of the plumbbob as its point wears away, and which when completely worn away can be withdrawn and replaced with no trouble and very slight expense. V

In the accompanying drawings, forming part of this specification, and in which similar letters of reference indicate similar parts throughout the several views, Figure 1 is a central sectional elevation of a plumb-bob, embodying my invention; Fig. 2, a central sectional elevation of a plumb-bob, showing a modification of my invention; and Fig. 3, a similar view showing another modification.

A is the plumb-bob, which is furnished with a threaded hole B, extending from its top down along its Vertical axis, as shown, to

' within a half-inch or an inch of its bottom.

C is the point or spindle, which is preferably furnished with a head D at its top, and which is smaller in diameter than the hole B, and is placed within this hole and passes to forming part of Letters Patent No. 485,376, dated November 1, 1892.

$erial No. 42411341 (No model.)

the outside of the plumb-bob through a hole E of about its own diameter, which extends from hole B to the smaller end or point of the plumb-bob.

F is a spring surrounding spindle G, which bears against the bottom of hole B and against the bottom of head D on this spindle, and G is ascrew, which travels on and is held by the threads on the hole B. This screw bears against the top of head D on spindle O, and by setting this screw down by means of a screw-driver the point of the spindle maybe advanced any distance desired beyond the plumb-bob. The spring F acts to prevent the spindle from advancing farther than is dietated by the screw G.

H is the top or cap of the plumb-bob, and is held in place by screwing it down in the hole B, this cap being furnished with a threaded projection I for this purpose, and with a hole K, passing through its center, through which the cord L, which carries the plumb-bob, may pass.

In the modification shown in Fig. 2 the spindle O is threaded, as is the hole E, and this spindle may be advanced by turning it by means of a screw-driver or key.

In the modification shown in Fig. 3 a spindle having a head D, similar to that shown in Fig. 1, is used. The plumb-bob is also furnished with a threaded hole B and with a screw M. This screw is furnished with a central hole M, through which the spindle 0 passes, its head resting on top of the screw M. G is a screw similar to the screw shown in Fig. 1, which bears against the head D of the spindle, and which prevents this spindle from being forced inward, while it is prevented from falling outward by the screw M. In order to advance the point, the screw G and spindle C are removed from the plumb-bob, the screw M is set down the requisite distance, and the spindle O and screw G are again put in place. The spindles 0 when worn away so as to be useless may be readily removed from the plumb-bobs and replaced by new ones.

Having thus described my invention, I claim- 1. The combination, in a plumb bob, of a body and a spindle within and projecting from said body and means, substantially as set forth, for advancing said spindle as its point wears away.

ing said spindle and bearing against said head and the bottom of said hole, substantially as IO 2. The combination, with a plumb-bob, of a set forth.

spindle within and projecting beyond said 5 p1umb-bob,a head on saidspiudle, athreaded hole, and a screw within said hole engaging the head of said spindle and adapted to move said spindle forward, and a spring surround- IIERBERT M. FULLER.

Witnesses:

CHRISTOPHER FALLON, CHAS. A. BUTTER. 

